module CanvasSync
  module Jobs
    # Starts a Canvas report and enqueues a ReportChecker
    class ReportStarter < CanvasSync::Job
      # @param report_name [Hash] e.g., 'provisioning_csv'
      # @param report_params [Hash] The Canvas report parameters
      # @param processor [String] a stringified report processor class name
      # @param options [Hash] hash of options that will be passed to the job processor
      # @param allow_redownloads [Boolean] whether you want the job_chain to cache this report,
      #   so that any later jobs in the chain will use the same generated report
      # @return [nil]
      def perform(report_name, report_params, processor, options, allow_redownloads: false)
        account_id = options[:account_id] || batch_context[:account_id] || "self"
        options[:sync_start_time] = DateTime.now.utc.iso8601
        options[:report_params] = report_params
        report_id = start_report(account_id, report_name, report_params)
        # TODO: Restore report caching support (does nayone actually use it?)
        # report_id = if allow_redownloads
        #               get_cached_report(account_id, report_name, report_params)
        #             else
        #               start_report(account_id, report_name, report_params)
        #             end

        batch = JobBatches::Batch.new
        batch.description = "CanvasSync #{report_name} Fiber"
        batch.jobs do
          CanvasSync::Jobs::ReportChecker.set(wait: report_checker_wait_time).perform_later(
            report_name,
            report_id,
            processor,
            options
          )
        end
      end

      protected

      # Ruby 3 changed how kwargs are handled. _kw_placeholder allows for backwards compatibility
      # In Ruby 2, merge_report_params(options, params) would parse as merge_report_params(options, params={}, **params) (wtf?), so
      # merge_report_params(options, params, {}) is used. That doesn't work in Ruby 3.
      # In order to maintain compatibility with 2 and with any apps, this oddness is needed
      def merge_report_params(options, params={}, _kw_placeholder=nil, term_scope: true)
        term_scope = options[:canvas_term_id] || batch_context[:canvas_term_id] if term_scope == true
        if term_scope.present?
          params[:enrollment_term_id] = term_scope
        end
        if (updated_after = batch_context[:updated_after]).present?
          params[:updated_after] = updated_after
        end
        params.merge!(options[:report_params]) if options[:report_params].present?
        params.merge!(options[:report_parameters]) if options[:report_parameters].present?
        { parameters: params }
      end

      private

      def get_cached_report(job_chain, account_id, report_name, report_params)
        # TODO: job_chain[:global_options] is no longer available and batch_context won't work for this
        if job_chain[:global_options][report_name].present?
          job_chain[:global_options][report_name]
        else
          report_id = start_report(job_chain, account_id, report_name, report_params)
          job_chain[:global_options][report_name] = report_id
          report_id
        end
      end

      def start_report(account_id, report_name, report_params)
        report = CanvasSync.get_canvas_sync_client(batch_context)
                           .start_report(account_id, report_name, report_params)
        report["id"]
      end
    end
  end
end